Portable electronic devices such as mobile phones, smart phones, personal digital assistants (PDAs), and tablets have become popular and ubiquitous. More and more features and applications have been added to these devices, including call, text, and e-mail functions, internet access, cameras, navigation applications, media storage and display applications, as well as others. These devices typically include a display with a graphics screen, such as a liquid crystal display (LCD) screen or panel, which generally needs a backlight in order for images to be visible. This is because LCDs do not produce light, unlike for example cathode ray tube (CRT) displays. Specifically, a backlight illuminates an LCD from the back or side of the display panel. Various types of backlights are known, including for example, incandescent light bulbs, light-emitting diodes (LEDs), an electroluminescent panel (ELP), one or more Cold Cathode Fluorescent Lamps (CCFL), or Hot Cathode Fluorescent Lamps (HCFL).
In some devices, backlights and the graphics panel are controlled to be turned off after a predetermined time period in order to conserve power, because many mobile devices are battery powered and these components can be a significant drain on the battery when turned on. Mobile electronic devices generally rely on a battery as a power source and therefore are sensitive to power draining components. A graphics screen backlight typically consumes an appreciable amount of power when illuminated and as such, can substantially reduce battery life (i.e., the time the battery will operate before it must be recharged). To reduce the power consumed by the backlight and graphics display screen during operation of a mobile device, it is desirable to provide a mobile device and method for proximity detection verification.
In addition, the portable electronic devices can also include touch screen displays that are controlled by a touch screen circuit that allows for touch inputs to be activated by a user. Touch screen displays can be subject to inadvertent actuation by a user when the device abuts a user's face such as when making a phone call. Therefore, a proximity sensor is often used to aid in identifying when a device is abutting a user's face. Because the proximity sensor is also subject to inadvertent actuation by a gesture performed by a user, it is desirable to provide a mobile device and method for proximity detection verification.